iMac Pro iMac 27 vs Macbook pro 13 with eGPU?

[dimzen]

I have an iMac 27 late 2013, was thinking about upgrading it, when Apple (hopefully) comes with a new iMac 2018-model

But just saw a youtube about eGPU on an Macbook Pro, I started thinking about how much Macbook Pro 13" + eGPU I could get for the same price as an iMac 27 with max CPU, 16GB ram and 512SSD.
And what performance CPU and GPU I would get, compared to the iMac.

As far as I can see, the Macbook Pro 13, only have a dual core CPU, where the 15" has a quard core, but not as high as the iMac 27 can get.
So the winner here is the iMac 27.

But what about GPU?
Would the eGPU win? Or would the iMac win, if I look at the total cost?

 

[SecuritySteve]

Well before you tabulate too much, remember that you need to factor in the cost of an additional monitor to use the eGPU with. You cannot use an eGPU on the built-in screen of an iMac or MacBook Pro (edit: currently).

 

[sputnikBA]

Depends on a combination of:

a) Spec of the iMac.
b) which models of GPU in iMac vs which model of GPU in the eGPU
c) what you want it to do / level of performance you need.
d) whether you will still need a second monitor for eGPU or if they can minimise the current performance penalties of looping back to the original display. (we won't know this until eGPU update for High Sierra comes out of beta in "spring 2018")

 

[dimzen]

a: The top iMac has Radeon Pro 580 8GB atm, I would think the 2018 one would have a better one, but if I just want to compare it with the current Mac's.
b: total cost of iMac vs MBP + eGPU and GPU.
c: that's want I want to figure out, how much GPU power would I get, if I paid the same as for the iMac
d: got a 2nd monitor to day, so I'm ignore that part.

 

[SecuritySteve]

a: The top iMac has Radeon Pro 580 8GB atm, I would think the 2018 one would have a better one, but if I just want to compare it with the current Mac's.
b: total cost of iMac vs MBP + eGPU and GPU.
c: that's want I want to figure out, how much GPU power would I get, if I paid the same as for the iMac
d: got a 2nd monitor to day, so I'm ignore that part.

Well heres my math, note that this is done in USD from the USA so noting that your profile says you're in Denmark, the exact price may likely vary:

Assumption: 2018 iMac topped out will cost about the same as the existing 2017 iMac topped out.
MBP = 1300 - 1800$
eGPU = 350$

iMac 27" with top GPU (no upgrades to CPU / storage / RAM) = 2300$

So assuming you got the minimum spec MBP at 1300, and the eGPU, that would put you at 1650$ - leaving you 650$ for a GPU. If you got the full spec MBP, you'd only have 150$ for the GPU, which wouldn't buy you anything worthwhile.

 

[dimzen]

Well heres my math, note that this is done in USD from the USA so noting that your profile says you're in Denmark, the exact price may likely vary:

Assumption: 2018 iMac topped out will cost about the same as the existing 2017 iMac topped out.
MBP = 1300 - 1800$
eGPU = 350$

iMac 27" with top GPU (no upgrades to CPU / storage / RAM) = 2300$

So assuming you got the minimum spec MBP at 1300, and the eGPU, that would put you at 1650$ - leaving you 650$ for a GPU. If you got the full spec MBP, you'd only have 150$ for the GPU, which wouldn't buy you anything worthwhile.

Thanks for the math, and yes I know the prices would be different in Denmark, but the math would properly still be about the same if comparing iMac vs Macbook.

Just looked at amazon, for 650$ I would be able to get a Geforce GTX 1080 (could I get better?), looks like it beats the Radeon Pro 580 in the current top GPU iMac.

So is there a downside, other then a lower CPU and not be able to upgrade ram (if we will be able to do that in the iMac 2018 model)?
The benefit would be laptop on the go, and bigger GPU at home

 

[SecuritySteve]

You could get the 1080, but my bet would be that AMD graphics cards will be the only cards supported in the High Sierra update coming later this spring (supposedly). You would probably be able to get a Vega 56 (close enough to a 1080) though.
(out of stock currently but link: https://www.newegg.com/Product/Prod...14137263&cm_re=Vega_56-_-14-137-263-_-Product)

You also don't get full performance from an external enclosure. Check this link out: https://egpu.io/forums/mac-setup/pcie-slot-dgpu-vs-thunderbolt-3-egpu-internal-display-test/

So factor those performance hits in, and check the benchmarks of a Vega 56 vs The Radeon Pro 580, and ask yourself if it's worth it.

Edit: Good comparison - http://gpuboss.com/gpus/Radeon-Pro-Vega-56-vs-Radeon-Pro-580

 

[sputnikBA]

I'm just gonna say that you are better off waiting until the eGPU support is out of beta and see what it means for what GPUS are supported officially and what performance improvements their are. They answers to those will change the balance of all of this anyway so its better to wait for the info.

 

[gian8989]

If your iMac is still running good just wait for the 2018 update.
eGPU is a good option only if you need the portability of the Macbook.

 

[dimzen]

Will wait for the 2018 iMac, this was more of a thought experiment